Humidification of respiratory gases

Abstract

A tub is configured to contain a supply of water and be inserted into a chamber of a humidifier. The tub includes a tub base configured to contain a supply of water and a tub lid connected to the tub base. The tub lid includes an inlet configured to receive a flow of breathable gas to be humidified and an outlet for the humidified flow of breathable gas. The tub further includes a water level indicator configured to indicate a level of the supply of water in the tub base. The water level indicator includes an inclined portion configured to direct the flow of breathable gas from the inlet away from the outlet. The water level indicator may be visible through the inlet.

What is claimed is: 
     
       1. A tub configured to contain a supply of water and to be coupled to a humidifier for a respiratory apparatus to humidify a flow of breathable gas during operation of the respirator apparatus, the tub comprising:
 a tub base configured to contain the supply of water; and 
 a tub lid connected to the tub base to form a tub chamber when the tub lid is in a closed position on the tub base, the tub lid comprising:
 a filling inlet configured to receive the supply of water to humidify the flow of breathable gas passing through the tub chamber; 
 an outlet for the flow of breathable gas after humidification; and 
 a non-removable water level indicator extending from the tub lid at the filling inlet and into the tub chamber such that when the tub is in an operational orientation and the tub lid is in the closed position on the tub base, contact between the supply of water contained by the tub base and the non-removable water level indicator is visible through the filling inlet to indicate a level of the supply of water in the tub base, wherein the non-removable water level indicator comprises a plurality of indicia or markings configured to indicate different water levels within the tub. 
 
 
     
     
       2. The tub of  claim 1 , wherein the plurality of indicia or markings have a maximum fill indicator that is visible through the filling inlet. 
     
     
       3. The tub of  claim 2 , wherein the maximum fill indicator is positioned on the non-removable water level indicator such that when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, the maximum fill indicator is positioned below an uppermost portion of the non-removable water level indicator. 
     
     
       4. The tub of  claim 2 , wherein the outlet has a tub chamber opening that is positioned inside of the tub chamber when the tub lid is in the closed position on the tub base, and
 wherein the maximum fill indicator is positioned on the non-removable water level indicator such that when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, the maximum fill indicator is positioned below the tub chamber opening. 
 
     
     
       5. The tub of  claim 2 , wherein the non-removable water level indicator has a distal end positioned opposite the tub lid and the maximum fill indicator is positioned on the non-removable water level indicator proximal to the tub lid such that the non-removable water level indicator becomes progressively more submerged during filling of the tub. 
     
     
       6. The tub of  claim 1 , wherein:
 the non-removable water level indicator comprises an inclined portion and a base portion, 
 the inclined portion extends from the base portion, and 
 the base portion extends from the tub lid adjacent to the filling inlet. 
 
     
     
       7. The tub of  claim 6 , wherein the base portion extends into the tub chamber when the tub lid is in the closed position. 
     
     
       8. The tub of  claim 6 , wherein the inclined portion comprises a first surface that is visible through the filling inlet and a second surface opposite the first surface, and
 wherein the inclined portion is angled with respect to the tub lid such that an angle between the second surface and a bottom plane of the tub lid is between just over 90° to just under 180°. 
 
     
     
       9. The tub of  claim 6 , further comprising a clip to releasably secure the tub lid to the tub base in the closed position. 
     
     
       10. The tub of  claim 6 , wherein the plurality of indicia or markings are configured to contact the supply of water contained by the tub base to indicate at least a maximum water fill level of the tub base when the tub is in the operational orientation and the tub lid is in the closed position on the tub base. 
     
     
       11. The tub of  claim 10 , wherein the plurality of indicia or markings are positioned on the inclined portion. 
     
     
       12. The tub of  claim 10 , wherein the plurality of indicia or markings include wording that is oriented parallel a longitudinal axis of the inclined portion so that the wording is progressively covered as the tub base is filled with water when the tub is in the operational orientation and the tub lid is in the closed position on the tub base. 
     
     
       13. The tub of  claim 12 , wherein the plurality of indicia or markings include a line adjacent the wording to contact the supply of water contained by the tub base to indicate the maximum water fill level when the tub is in the operational orientation and the tub lid is in the closed position on the tub base. 
     
     
       14. The tub of  claim 1 , wherein the tub lid comprises a channel configured to receive the flow of breathable gas from a flow generator, the channel comprising a channel inlet and a channel outlet. 
     
     
       15. The tub of  claim 14 , wherein the tub lid comprises a cover portion that covers the channel from the channel inlet to the channel outlet. 
     
     
       16. The tub of  claim 1 , wherein the non-removable water level indicator is integrally formed in one piece with the tub lid. 
     
     
       17. The tub of  claim 1 , wherein the tub base further comprises a metal portion. 
     
     
       18. The tub of  claim 17 , wherein the metal portion comprises stainless steel or aluminum. 
     
     
       19. The tub of  claim 1 , wherein the tub lid is formed of a plastic. 
     
     
       20. The tub of  claim 19 , wherein the plastic is polycarbonate or acrylonitrile butadiene styrene (ABS). 
     
     
       21. The tub of  claim 1 , wherein each of the tub base and the tub lid is transparent or translucent. 
     
     
       22. The tub of  claim 1 , further comprising:
 a seal provided between the tub base and the tub lid. 
 
     
     
       23. The tub of  claim 1 , wherein:
 wherein the plurality of indicia or markings have a maximum fill indicator that is visible through the filling inlet, 
 the non-removable water level indicator comprises an inclined portion and a base portion, 
 the inclined portion extends from the base portion, 
 the base portion extends from the tub lid adjacent to the filling inlet, 
 the base portion extends into the tub chamber when the tub lid is in the closed position, 
 the tub further comprises a clip to releasably secure the tub lid to the tub base in the closed position, 
 the plurality of indicia or markings configured to contact the supply of water contained by the tub base to indicate at least a maximum water fill level of the tub base when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, 
 the plurality of indicia or markings are positioned on the inclined portion, 
 the plurality of indicia or markings include wording that is oriented parallel a longitudinal axis of the inclined portion so that the wording is progressively covered as the tub base is filled with water when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, 
 the plurality of indicia or markings include a line adjacent the wording to contact the supply of water contained by the tub base to indicate the maximum water fill level when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, 
 the non-removable water level indicator is integrally formed in one piece with the tub lid, 
 the tub base further comprises a metal portion, 
 the tub lid is formed of a plastic, and 
 each of the tub base and the tub lid is transparent or translucent. 
 
     
     
       24. The tub of  claim 23 , wherein the inclined portion comprises a first surface that is visible through the filling inlet and a second surface opposite the first surface, and
 wherein the inclined portion is angled with respect to the tub lid such that an angle between the second surface and a bottom plane of the tub lid is between just over 90° to just under 180°. 
 
     
     
       25. An integrated humidifier and positive airway pressure (PAP) device for providing a pressurized and humidified flow of breathable gas to be delivered to a patient at a pressure of about 2-30 cm H 2 O, the integrated humidifier and PAP device comprising:
 a chamber configured to receive the flow of breathable gas; 
 a humidifier lid hinged to the chamber, the humidifier lid being movable between an open position and a closed position; 
 a humidifier seal configured to seal the chamber such that the flow of breathable gas pressurizes the chamber; 
 the tub of  claim 1  configured to be inserted into the chamber; and 
 a flow generator configured to generate the flow of breathable gas. 
 
     
     
       26. The integrated humidifier and PAP device of  claim 25 , wherein:
 the chamber comprises a cradle, 
 the cradle comprises a cradle inlet configured to receive the flow of breathable gas from the flow generator, and 
 the cradle comprises a cradle outlet configured to be connected to an air delivery conduit, the cradle outlet configured to supply the pressurized and humidified flow of breathable gas. 
 
     
     
       27. An integrated humidifier and positive airway pressure (PAP) device for pressurizing and humidifying a flow of breathable gas to be delivered to a patient at a pressure of about 2-30 cm H 2 O, the integrated humidifier and PAP device comprising:
 a flow generator configured to generate a flow of breathable gas, 
 a chamber configured to receive the flow of breathable gas; 
 a humidifier lid hinged to the chamber, the humidifier lid being movable between an open position and a closed position; 
 a tub removable from the chamber, the tub comprising:
 a tub base configured to contain a supply of water; and 
 a tub lid connected to the tub base to form a tub chamber when the tub lid is in a closed position on the tub base, the tub lid comprising:
 a filling inlet configured to receive the supply of water to humidify the flow of breathable gas passing through the tub; 
 an outlet for the flow of breathable gas after humidification; and 
 a non-removable water level indicator extending from the tub lid at the filling inlet and into the tub chamber such that when the tub is in an operational orientation and the tub lid is in the closed position on the tub base, contact between the supply of water contained by the tub base and the non-removable water level indicator is visible through the filling inlet to indicate a level of the supply of water in the tub base, wherein the non- removeable water level indicator comprises a plurality of indicia or markings configured to indicate different water levels within the tub; and 
 
 
 a humidifier seal positioned between the tub and the humidifier lid when the humidifier lid is in the closed position. 
 
     
     
       28. The integrated humidifier and PAP device of  claim 27 ,
 wherein the plurality of indicia or markings have a maximum fill indicator that is visible through the filling inlet. 
 
     
     
       29. The integrated humidifier and PAP device of  claim 28 , wherein the maximum fill indicator is positioned on the non-removable water level indicator such that when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, the maximum fill indicator is positioned below an uppermost portion of the non-removable water level indicator. 
     
     
       30. The integrated humidifier and PAP device of  claim 28 , wherein the outlet has a tub chamber opening that is positioned inside of the tub chamber when the tub lid is in the closed position on the tub base, and
 wherein the maximum fill indicator is positioned on the non-removable water level indicator such that when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, the maximum fill indicator is positioned below the tub chamber opening. 
 
     
     
       31. The integrated humidifier and PAP device of  claim 28 , wherein the non-removable water level indicator has a distal end positioned opposite the tub lid and the maximum fill indicator is positioned on the non-removable water level indicator proximal to the tub lid such that the non-removable water level indicator becomes progressively more submerged during filling of the tub. 
     
     
       32. The integrated humidifier and PAP device of  claim 27 , wherein:
 the non-removable water level indicator comprises an inclined portion and a base portion, 
 the inclined portion extends from the base portion, and 
 the base portion extends from the tub lid adjacent to the filling inlet. 
 
     
     
       33. The integrated humidifier and PAP device of  claim 32 , wherein the base portion extends into the tub chamber when the tub lid is in the closed position. 
     
     
       34. The integrated humidifier and PAP device of  claim 32 , wherein the inclined portion comprises a first surface that is visible through the filling inlet and a second surface opposite the first surface, and
 wherein the inclined portion is angled with respect to the tub lid such that an angle between the second surface and a bottom plane of the tub lid is between just over 90° to just under 180°. 
 
     
     
       35. The integrated humidifier and PAP device of  claim 32 , further comprising a clip to releasably secure the tub lid to the tub base in the closed position. 
     
     
       36. The integrated humidifier and PAP device of  claim 32 ,
 wherein the plurality of indicia or markings are configured to contact contained by the tub base the supply of water to indicate at least a maximum water fill level of the tub base when the tub is in the operational orientation and the tub lid is in the closed position on the tub base. 
 
     
     
       37. The integrated humidifier and PAP device of  claim 36 , wherein the plurality of indicia or markings are positioned on the inclined portion. 
     
     
       38. The integrated humidifier and PAP device of  claim 36 , wherein the plurality of indicia or markings include wording that is oriented parallel a longitudinal axis of the inclined portion so that the wording is progressively covered as the tub base is filled with water when the tub is in the operational orientation and the tub lid is in the closed position on the tub base. 
     
     
       39. The integrated humidifier and PAP device of  claim 38 , wherein the plurality of indicia or the markings include a line adjacent the wording to contact the supply of water contained by the tub base to indicate the maximum water fill level when the tub is in the operational orientation and the tub lid is in the closed position on the tub base. 
     
     
       40. The integrated humidifier and PAP device of  claim 27 , wherein the tub lid comprises a channel configured to receive the flow of breathable gas from the flow generator, the channel comprising a channel inlet and a channel outlet. 
     
     
       41. The integrated humidifier and PAP device of  claim 40 , wherein the tub lid comprises a cover portion that covers the channel from the channel inlet to the channel outlet. 
     
     
       42. The integrated humidifier and PAP device of  claim 27 , wherein the non-removable water level indicator is integrally formed in one piece with the tub lid. 
     
     
       43. The integrated humidifier and PAP device of  claim 27 , wherein the tub base further comprises a metal portion. 
     
     
       44. The integrated humidifier and PAP device of  claim 43 , wherein the metal portion comprises stainless steel or aluminum. 
     
     
       45. The integrated humidifier and PAP device of  claim 27 , wherein the tub lid is formed of a plastic. 
     
     
       46. The integrated humidifier and PAP device of  claim 45 , wherein the plastic is polycarbonate or acrylonitrile butadiene styrene (ABS). 
     
     
       47. The integrated humidifier and PAP device of  claim 27 , wherein each of the tub base and the tub lid is transparent or translucent. 
     
     
       48. The integrated humidifier and PAP device of  claim 27 , further comprising:
 a seal provided between the tub base and the tub lid. 
 
     
     
       49. The integrated humidifier and PAP device of  claim 27 , wherein:
 wherein the plurality of indicia or markings have a maximum fill indicator that is visible through the filling inlet, 
 the non-removable water level indicator comprises an inclined portion and a base portion, 
 the inclined portion extends from the base portion, 
 the base portion extends from the tub lid adjacent to the filling inlet, 
 the base portion extends into the tub chamber when the tub lid is in the closed position, 
 the tub further comprises a clip to releasably secure the tub lid to the tub base in the closed position, 
 the plurality of indicia or markings configured to contact the supply of water contained by the tub base to indicate at least a maximum water fill level of the tub base when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, 
 the plurality of indicia or markings are positioned on the inclined portion, 
 the plurality of indicia or markings include wording that is oriented parallel a longitudinal axis of the inclined portion so that the wording is progressively covered as the tub base is filled with water when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, 
 the plurality of indicia or markings include a line adjacent the wording to contact the supply of water contained by the tub base to indicate the maximum water fill level when the tub is in the operational orientation and the tub lid is in the closed position on the tub base, 
 the non-removable water level indicator is integrally formed in one piece with the tub lid, 
 the tub base further comprises a metal portion, 
 the tub lid is formed of a plastic, and 
 each of the tub base and the tub lid is transparent or translucent. 
 
     
     
       50. The integrated humidifier and PAP device of  claim 49 , wherein the inclined portion comprises a first surface that is visible through the filling inlet and a second surface opposite the first surface, and
 wherein the inclined portion is angled with respect to the tub lid such that an angle between the second surface and a bottom plane of the tub lid is between just over 90° to just under 180°.